Evaluation of the seismic performance of buildings is often conducted as a first step of a risk mitigation process for an existing building. The issue of seismic evaluation of existing buildings has become increasingly important in recent decades, especially in the context of performance-based design. The purpose of this evaluation is to assess and/or predict the building's behaviour during an earthquake or other seismic event, to identify whether the structure is in need of preventive retrofit, and to provide a reference condition to recognize damage in the building after the occurrence of a design-level earthquake.
Typical seismic response assessment methods for buildings are based on linear and nonlinear static and/or dynamic analysis approaches. However, according to one survey conducted on the topic of seismic response assessment methods in structural engineering firms in the United States, the results obtained from the numerical models of the existing approaches are inherently uncertain and variable, as different analysis methods lead to significantly different results. Moreover, the general complexity of existing methods, the sensitivity of the inelastic analysis approaches to assumptions regarding such parameters as initial stiffness, and the invariance of the loading patterns used in nonlinear static analysis procedures are also shortcomings of existing seismic response assessment methods.
Therefore, there is a need for developing alternative simplified seismic evaluation methods.